Answer:
F = 196 N
Explanation:
For this exercise we will use Newton's second law, we define a reference system with the x axis in the direction of movement of the stones and the y axis vertically
Y axis
N- W = 0
N = mg
X axis
F -fr = ma
In this case, they ask us for the force to keep moving, so the stones go at constant speed, which implies that the acceleration is zero.
F- fr = 0
F = fr
the friction force has the equation
fr = μ N
fr = μ mg
we substitute
F = μ mg
let's calculate
F = 0.80 9.8 25
F = 196 N
The correct option is C) The angle between the vectors is 120°.
Why?
We can solve the problem and find the correct option using the Law of Cosine.
Let A and B, the given two sides and R the resultant (sum),
Then,
So, using the law of cosines, we have:
Hence, we have that the angle between the vectors is 120°. The correct option is C) The angle between the vectors is 120°
Have a nice day!
Answer:
t = 8 s
Explanation:
In order to find the time taken by the dragster we will use equations of motion. Here, we will use second equation of motion:
s = Vi t + (1/2)at²
where,
s = distance covered = 320 m
Vi = Initial Velocity = 0 m/s (Since, dragster starts from rest)
t = time taken = ?
a = acceleration of dragster = 10 m/s²
Therefore,
320 m = (0 m/s)t + (1/2)(10 m/s²)t²
t² = (320 m)(2)/(10 m/s²)
t = √(64 s²)
<u>t = 8 s</u>
A) <span>Ivan does work when he lifts the basket
B) Work = Force * displacement
W = 20 * 2
W = 40 Joules
So, The Amount of work he does is 40 Joules
Hope this helps!</span>
